I never cease to be amazed at the basic innumeracy of some of those who oppose wind power in Wales, or at the readiness of the Welsh media to provide space for them to display their idiocy. Yesterday, Wales Online carried a story under this headline:

Anger over claim huge new wind farm will power third of Welsh homes

The person pouring scorn on the claim was a John Lawson-Reay of Save our Scenery, who said:

"The only time they might provide anything near that power is when the wind is at gale force.

“It has to be force seven for them to have the full output and most of the time the turbines are not turning enough because despite what they claim we don’t have as much wind as they like to think we have.”

Let's do some basic maths. The installed capacity of Gwynt y Môr is 576 MW. This means it has the potential to generate 576 x 24 x 365 MWh of electricity in a year. The operators believe it will produce 1,950 GWh a year, which it would achieve at a capacity factor of 38.6%. That's certainly well within the realms of possibility for an offshore wind farm, although to be safe it might be better to use a more conservative capacity factor of 35% (this is the normal average achieved by North Hoyle, for example) which would result in a production figure of 1,766 GWh a year.

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I've never had time for expressing electricity generation in terms of how many homes it will supply. It's confusing and I think it's always better to deal in precise units. But for what it's worth the figure that has most generally been used is 4,700 kWh/yr and on that basis Gwynt y Môr will provide electricity for 375,000 to 415,000 homes without taking transmission losses and the like into account. However the latest DECC estimate puts average household consumption at 3,300 kWh/yr, varying from a low of 2,100 kWh/yr to a high of 5,100 kWh/yr.

This wide variation means people can make all sorts of claims and counter-claims. But it's certainly not unreasonable to say that Gwynt y Môr will provide electricity for a third of the homes in Wales ... so long as we bear in mind that domestic consumption only accounts for about 35% of final consumption and 30% of the total supply of electricity, as shown here.

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I think it's more helpful to look at things in this way. In round terms, we need to generate just under 20 TWh of electricity a year to meet Wales' needs. Gwynt y Môr will generate between 9% and 10% of it.

26
comments:

Anonymous
said...

Gwynt y Mor, like any other wind based scheme, does not provide baseload. It will require back-up power and is therefore hugely wasteful. Would you buy a car which only worked on three days a week? Here in mid-Wales, wind power stations only produce power for 19% of the time

"But it's certainly not unreasonable to say that Gwynt y Môr will provide electricity for a third of the homes in Wales."

I'm afraid I do not agree - I would say:"But it's certainly not unreasonable to say that Gwynt y Môr will provide electricity for a third(**) of the homes in North Wales and Cheshire when the wind blows."

(**) no, I have not worked out the exact percentage, but I'm sure you get my point.

I don't want any onshore windfarms for the simple reason - they destroy our beautiful landscape. One of our big industries is tourism and people don't want to see a bunch of white posts. People forget this point all the time but I think it's important.

Off shore wind farms are a bit better but from what I read they are not efficient.

One of the crazy things about wind farms is that if there is 'too much' wind companies will pay the producers to not produce power (as it is so much more expensive to buy electric from these than say nuclear). How on earth do people find this ok?.

There are 8,760 hrs in year. Our electric kettle is rated at 3kw. So on your figures, 3,300kwh per year per houshold, the kettle would use up my total "allowance in 1,100 hrs. I know our kettle is not continuously boiling, but I often wonder at these claims foe X number of housholds per year.The car, mentioned above, that only works for 3 days a week is only part of the story. In fact, you will never know when those three days are going to be. So you will need another car to take you where you want to go, when you want to go there. We should dump these ineffective means of generating electricity and concentrate our efforts and our cash on hydro. Oh, and by the way, the next time someone says wind is the only renewable technology that is developed enough to use at the moment point out to them that hydro electricity has been around for over 100 years.

I'm sceptical about windfarms but many people are protesting against it for the wrong reasons. It's ridiculous to talk about the effect of windfarms on the natural landscape. Wales is a nation, not a (British) national park. If this drives down tourism then I'm all for it. Wales needs real jobs and development, these 'green' obsessions are fragmenting our nation.

Build a motorway through the Elenydd, linking Ynys Mon, Gwynedd and Ceredigion to Swansea Bay, the Valleys and Cardiff.

"Will the electricity produced by Gwynt y Mor be used to power a 'third of Welsh homes'? Or will it be use to power homes equalling a 'third of Welsh homes'?"It's the second (in theory). It's just basic innumeracy and idiocy of pro-wind campaigners...!

As expected, many of the comments demonstrate the very same idiocy displayed in the Wales Online article. It's hard to know whether the comments are deliberately designed to misinform or based on ignorance but, either way, it doesn't make any difference to the facts.

This one windfarm will produce between 9% and 10% of the electricity Wales needs.

Got no problem with offshore wind power in principle. The capacity factor for offshore is better than onshore, although of course consideration needs to be be given to environmental impacts on the marine side.

A commenter above refers to hydro-electric generation as a more reliable alternative to wind. I'm a huge fan of micro-hydro, but what needs to be borne in mind is that small-scale hydroelectric generation is no more or less reliable that wind. Output is highly dependent on seasonal rainfall conditions.

This aside, it's likely that WAG have grossly underestimated our small-scale hydroelectric capacity, and it's not unfeasible that we could probably remove one of the smaller Strategic Search Areas in TAN8 and replace it with capacity provided from micro-hydro.

As to the first comment about baseload - therein lies the fundamental problem of WAG's renewable energy strategy. It's build around a fundamentally flawed model of onshore wind supplemented by gas-fired baseload generation. Of course, the fact that the gas-fired baseload capacity under consent/construction across Wales will largely outstrip ANY of our consented/under construction renewable capacity means that any talk of "energy independence" or "climate change" mitigation in a Welsh context is pretty academic...

I don't want to be too critical of what you've said, Jim, for I certainly agree that we should be developing other forms of renewable energy, and micro-hydro is one of those. But I do want to pick up on the idea of baseload generation, for I think it is an anachronism and widely misunderstood.

It is anachronistic because it is more suited to times when the bulk of electricity generation was coal and nuclear, since it is virtually impossible to control the output of either to account for variations in the pattern of demand for electricity. Because of this uncontollability we saw the widespread use of electric storage heaters in the home making use of white meters, and the construction of pumped hydro storage schemes. Dinorwig would never have been built if it wasn't for the very real problem of nuclear energy being churned out at times when it wasn't of any use - for the uncontrolability of nuclear is every bit as much of a problem as the intermittency of wind. Then later, as we made more use of gas from the North Sea, we saw nuclear and coal as providing a more or less continuous amount of electricity equal to the the lowest level of consumption (the early hours of the morning) with gas then able to provide a variable amount of electricity in line with the degree of variation in demand.

Coal and nuclear provided the "baseload" and gas was used for, to use the jargon, "load following" generation. So I smiled at the idea of "gas-fired baseload capacity". Yet it is one of those stupid ideas that has been taken hold of in recent years. For with the demise of coal and nuclear, governments are tending to think of gas (which now accounts for 41% of the total UK electricity supply, see the DECC link in the main post) as a means of supplying "baseload" capacity. It's stupid because gas is in fact the second worst way of doing this, after hydro. Gas needs to be used more cleverly.

Essentially we need to ditch the concept of baseload, and look at things from a completely different angle to suit current realities rather than those of the 60s.

Rather than coal and nuclear being seen as the fixed points in the system, which every other form of generation must fit itself around, we increasingly need to be lookng at intermittent forms of energy as the things that other forms of generation must fit themselves around. With such a way of looking at things, gas and hydro (or to be specific gas and dammed hydro; for run-of-the-river hydro, which accounts for most micro schemes, isn't controlable) become the main means of providing the electricity we need when intermittents aren't producing. To me, the most sensible way of using gas and dammed hydro is in load following mode.

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If a parallel is to be drawn with cars, it is this. The aim of developing and encouraging alternative forms of transport to the car is not to do away with cars. Most people who have cars will still need them sometimes for some things. The point is to use them less often. And yes, that does mean that more cars will be sitting idle in people's garages and driveways for more of the time. Some might call that "inefficient", and I guess it is; but it's a good thing because it will save us money and do less damage to the environment.

It's the same with gas-fired power stations. Whether we like it or not, we have plenty of gas-fired power stations, some of which (like SevernPower and Pembroke) are new. For the next few decades, the aim is not to close these gas-fired station any more than it is to get rid of private cars. The point is to use them less often. And yes, that does mean that more gas-fired stations will be sitting idle for more of the time. Some might call that "inefficient", and I guess it is; but it's a good thing because it will save us money and do less damage to the environment.

iii. denied financial benefits as R&D and fabrication are undertaken outside Wales, and large subsidies are paid directly into the bank accounts of foreign companies...

What is the benefit to the Welsh public of expanding this unpopular method of energy production which fails to address the issues of baseload?

If the growth of wind farms produced significant benefits to a large number of the Welsh public (particularly in terms of large numbers of well paid and sustainable jobs) they would be popular and uncontroversial. You do a disservice to people who care for the future of their communities and environment when you dismiss them as irrational. While some climate sceptics are clearly loonies it is mendacious to try and tar all opponents with the same brush.

Wind power is enormously emotive and for the most part the down right lies and distortions are on the side of the antis. The Western Mail carried a letter from someone claiming that replacing a bearing on an off shore turbine was more hazardous, more time consuming and more expensive than replacing a bearing in a turbine in a nuclear power station. Then there is the claim that they use more electricity than they generate.

The reality is that we need a mix, we have great resources for wind generation, mainly but not entirely off sore. Yes it isn't base load - but then neither strictly is gas, as nicely explained by MH. One storage mechanism for intermittent electricity generated by wind and other sources will be in electric cars - their storage batteries will charge overnight (when the wind blows and when demand is low). In the following decades electric powered cars will become far more numerous than they are now. We may even see greater home storage of electricity - as we move to more solar systems and the feed in tariffs are removed, these storage systems again can be used as part of "smart grids" to store and distribute electricity.

There are a number of excellent storage solutions already in existence and many more on the drawing board. This is not an insurmountable problem.

I wouldn't dismiss the claim that replacing a bearing in a turbine in a nuclear power station is less expensive and hazardous than doing the same in an offshore wind turbine, Cibwr. It would be. The steam turbines in a nuclear station are simple, straightforward pieces of machinery and, being on land, they are easy to get at and fix. The problem with nuclear isn't the turbines, it's the nuclear reactors that produce the heat that produces the steam to turn those turbines ... and a couple of dozen other problems to do with radiation, storage, cooling, safety systems, etc, etc, etc. That's what makes nuclear expensive and hazardous.

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I agree with you entirely on the progress of smart, demand-side, electrical storage solutions. Not just electric cars, but things like this. People might be interested to know that there is a group working towards making this a priority at a policy/legislative level, here.

But as things stand, we in Wales have the capacity to do things at a supply-side level that most other countries can't. The most efficient form of mass storage is dammed hydro, and Wales has water and mountains in abundance. But we use it in the wrong way. At present we use them to produce a small amount of elctricity every day emptying on an annual cycle to match the seasons (lowest water levels in late summer). We could, by installing more turbines but not increasing the size of the reservoir, use them to provide much more energy over a shorter period of days, rather than of months. This could help solve the problem of the wind not blowing anywhere in Wales for a few days without needing to resort to fossil fuel gas fired backup.

And in fact not all methane is fossil fuel based. Landfill gas has been a significant part of renewable energy production for some time (along with sewage gas it produces more renewably generated electricity than wind in England, or at least it did in 2009) but we can get far more of it by better waste management and more anaerobic digestion of organic waste.

Anon "I'm a huge fan of micro-hydro, but what needs to be borne in mind is that small-scale hydroelectric generation is no more or less reliable that wind. Output is highly dependent on seasonal rainfall conditions."

I wasn't referring specifically to "micro-hydro" but even that is more consistant than wind. River flow might vary, but it very rarely actually stops.

I have heard this on many occasions, but never with an explanation as to why. Why would you deliberately include a less effective option in the mix? It is a mantra, possibly dreamed up by some wind generator manufacturer’s PR department.

Those old industrialists, pre steam power, didn’t use water to power their factories by accident. They knew it was more reliable that wind. Nobody said we’ll throw in a few windmills because we need a mix.

I can see the attraction of combining wind power generation with pumped-storage hydroelectric schemes, but you have to remember that Dinorwig (for example) runs on average at 74-75% efficiency - i.e. it uses 33% more electricity than it actually produces.

Your panasonic battery is interesting (but again, uses more elecricity than it produces). It does not help against the biggest problem I have with wind generation - the cost to the customer, and the resultant increase in fuel poverty.

You should know better than to quote figures without providing a link to them, Ioan. You're welcome to repost your 13:36 figures if you can back them up.

I won't quibble about your figure for Dinorwig, because it's about right. But no storage is 100% efficient, at least in physical terms. The point of such storage is that it works in economic terms because the price of electricity varies throughout the day. The idea is to use cheap electricty in the early hours to pump water up, then sell expensive electricity at peak hours; on that basis it might well make an operating profit, but I've not seen any figures. However the second part of the equation is to consider the cost of the alternative, i.e. how much it would cost to install "peaking" turbines running on gas ... and, of course, how much less efficient such turbines are because they operate intermittently.

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As for cost to the customer, there are many things that could be said. However the big picture is that we cannot and should not ignore the cost of other fuels when the damage they cause is taken into account. If we believe in the principle that the polluter should pay, then it is only right that producers of electricity should be charged for the CO2 and other pollutants they put into the atmosphere. That in itself would push up the price of electricity produced by burning coal and gas. We don't yet have a working carbon trading scheme, but subsidies in the form of ROC trading are designed to achieve the same thing. There might be plenty to criticize in the details, but the underlying principle is fair.

From a different angle, people might also remember that Haf Elgar of FoE Cymru made the point that fossil fuels receive a far greater subsidy than renewables at Plaid's spring conference this year. But if not, the video and links are here.

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